Electromagnetic system for railroad track crack detection and traction enhancement

ABSTRACT

An electromagnetic system for detecting cracked rail and enhancing traction when necessary, includes wiring coils around wheel axles, and a corresponding power source for supplying power to the coils for producing electromagnetic flux. The produced electromagnetic flux is routed through the wheel axles, wheels and rails in a closed circuit. When a cracked rail is encountered along the route, the circuit will be interrupted or open, resulting in a changed flux pattern. This pattern change is detected by a flux sensor, and the geographic location of the crack in the rail is determined. The electromagnetic system further includes an electromagnetic wheel loading means for generating an attraction to the rails. The generated attraction to the rails increases friction between the wheels and the rails, thereby increasing traction to enable hauling greater loads up steep grades.

TECHNICAL FIELD

This invention relates to train rail crack detection and tractionenhancement and, more particularly, to detection of a cracked train railby magnetic flux and, additionally, to the increase of traction betweena train wheel and the rail, again by magnetic flux.

BACKGROUND ART

Cracked rails occur in various geographical areas, in various climates,and at various locations where the rail beds are in less than optimalcondition. Undetected cracked rails can cause derailment along withlife-threatening danger and equipment damage. Currently, ten mile areasof rail track are probed before a train is allowed to go on the track.The probing creates a delay and backup in freight car areas and inlocomotive dispatching, where cost to shipping is added due to theseidle waiting rail cars.

It is desirable to know the condition of a section of track as the trainleaves that section of the track. Self-policing track by simple low costmeans for the next user, which may be closer than the ten mile probearea, would allow closer spacing of trains and thus increase throughputof coal etc., throughout the rail system.

All sorts of schemes have been conceived to detect cracks in a rail, butnone appear to be cost effective. Ultrasound, and the like, employdetectors to screen out known discontinuities in track matingtechniques, but none are cost effective to date.

Further problems occur when train locomotives pull heavy loads undervarious types of weather, track condition, etc. Wheel slippage causesdamage to tracks and wheels themselves. Various techniques have beentried to detect loss of traction as well as slippage and re-direct powerto the non-slipping wheels. This resembles the limited slip or tractioncontrol offered in many automobiles. Such techniques have had varyingdegrees of success.

It is desired to greatly increase traction to enable locomotives to pullgreater loads up hills. Maintenance of damaged wheels and track due toslippage is time-consuming and costly. Therefore, the desire to minimizeor eliminate slippage is another issue for the subject of the presentinvention.

SUMMARY OF THE INVENTION

A method to detect train rail cracks easily, and at low cost, isimplemented with a circuit for detection of cracks in train rails andrail discontinuity. The invention provides both train truck andtrailering embodiments for rail crack detection with little complexity.

The invention also involves use of a method of magnetraction to inhibitslippage between train wheel and track, using electromagnetic energywith no current in or through the train axle bearing. The method usesopposing electromagnetic fields to generate and complete the magneticcircuit, enabling both aspects of this invention to take place. Anelectromagnet structure is used to pull the train locomotive downwardtoward the track, thus increasing the loading force on the wheel,producing greater friction and therefore improved traction. A trainoperator can apply this magnetraction at will, or under computercontrol.

A preferred embodiment of the invention combines a crack detector andtraction enhancement concept for locomotive and end of train crackdetection. The magnetic structure force enhancer is placed where it willnot interfere with proper operation of the train. Additionally, theinvention provides a way to use electromagnetic energy that does notrequire electric current in the bearing assemblies of the train axles.

An electromagnetic system for rail detection and traction enhancementcomprises, in a preferred embodiment, wheel axles, wiring coils aroundthe wheel axles, respectively, and a power source coupled to the wiringcoils for supplying power to produce electromagnetic flux. The wiringcoils produce opposite magnetic north and south pole pairs on the axles.

The electromagnetic system further comprises means for monitoring a fluxpattern if different, interrupted or open, and means for locating theposition where the circuit pattern is detected as open. The power sourceis a generator for generating power by wheel rotation, or by alocomotive engine. The system further includes an electromagnetic wheelloading means connected to said power source, for generating artificialload of a train.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of the invention;

FIG. 2 is a schematic view of the invention illustrating a situationwhere the rail is cracked;

FIG. 3 is a pictorial diagram of an embodiment of the inventionpresented as a trailer module;

FIG. 4 is a block diagram of the system of the invention;

FIG. 5 illustrates the flux field expanding to the traction area; and

FIG. 6 is a partial schematic view of the invention employing anelectromagnet for pulling the train downward to make it artificiallyheavier.

PREFERRED EMBODIMENT OF THE INVENTION

FIG. 1 illustrates a preferred embodiment of the invention. Theschematic view shows an ordinary railroad track having train rails 11 aand 11 b and rail ties 12. Train wheels 23 a, 23 b, 23 c, and 23 d areplaced on, and contact, rails 11 a and 11 b. The train wheels may bepart of a train truck carriage (or a trailering carriage).

FIG. 1 further illustrates wiring coils 22 a, 22 b placed around wheelaxles 21 a, 21 b, respectively. A power generator 24 supplies current towiring coils 22 a, 22 b for generating electromagnetic flux. Thesefluxes are preferably out of magnetic phase with each other, producingnorth-south opposing pairs of magnetic poles 31 a, 32 a and 31 b, 32 b.More particularly, magnetic pairs 31 a, 32 a of wheel axle 21 a areopposite to magnetic pairs 31 b, 32 b of the wheel axle 21 b. Therefore,wheel axles 21 a, 21 b and corresponding portions of rails 11 a and 11 bform a closed magnetic or electromagnetic circuit pattern through thecontacts made by the wheels. The magnetic or electromagnetic circuit isencompassed within an area that moves along the track with the vehicleon which it is carried. The magnetic flux is continuous among magneticpole pairs 31 a, 32 a, and 31 b, 32 b, so that the magnetic flux issmooth in the route of the closed electromagnetic circuit. Importantly,there is no electrical current to pass through the bearing assembliesfrom the power generator, thereby avoiding potential damage to thebearing assemblies.

Generator 24 may be powered by the locomotive prime mover, which maycomprise a diesel engine or electric motor, or, alternatively, may be aninternal generator that is turned by one of the wheels itself, eitherway thus generating the electrical current for energizing theelectromagnetic circuit. It will also be noted that permanent magnetscan accomplish this function by magnetizing the wheel assembly.

Monitoring means, such as a magnetometer or other flux sensor 25 isutilized to monitor the magnetic circuit pattern. In non-cracked railareas, a magnetic flux path is induced in the wheel axle which continuesthrough the train rail and passes back through the wheel and second axleassembly, closing a magnetic loop, namely, north pole through the railto south pole, through the axle, to north pole etc. The flux induced inthe electromagnetic circuit will be smooth and continuous if no crackedrail is encountered as the electromagnetic circuit is moved along thetrack.

However, as illustrated in FIG. 2, if a crack 13 in the rail, apartially cracked rail, or other discontinuity in the rail isencountered, and the electromagnetic circuit passes over this area, aninterrupted, open, or very different circuit pattern will be monitored.The flux sensor marks this discontinuity and notes its geographiclocation by employing, for example, a GPS (Global Positioning System)locator, odometer and track database, or the like. A ground crew canthen be dispatched to investigate and repair the cracked rail. As afurther refinement, the discontinuity can be compared to a trackdatabase to identify known track breaks at isolation joints which do notrequire repair.

FIG. 3 illustrates application of the aforementioned procedure. Theinvention is implemented in a tail module 33 and powered by thelocomotive engine. When a cracked rail is detected, the locating means,such as a GPS locator with an antenna 34, generates the position of thecracked rail for future inspection and repair. Tail module 33 may beplaced in at various locations in the train consist; i.e., it may trailthe train, as illustrated in FIG. 3, it may lead the locomotive or itmay be part of the locomotive. The magnetic flux may be low so as not topull debris inside the track area, such as loose rail spikes, etc.

FIG. 4 illustrates the electrical system for detecting the broken rail.An electromagnet drive circuit 41 (including generator 24 of FIG. 1)provides the electromagnetic flux to wheel axles 21 a, 21 b throughwiring coils 22 a, 22 b, respectively. Thus, through the correspondingrail and contacts made by the wheels, an electromagnetic circuit isachieved. Broken rail detection circuit 42 (e.g., flux sensor 25 ofFIG. 1) monitors the electromagnetic circuit pattern to determine if thepattern is changed or interrupted. If a discontinuity or differentpattern is detected, a broken rail signal is passed to a control circuit43. Control circuit 43 acquires a position from GPS locating andreporting circuit 44, and combines and formats the broken rail signalfrom detection circuit 42 with the position information from the GPSlocator of circuit 44. The combined and formatted signal is transferredto an output circuit 45 for producing a locomotive cab alert and/oractivating a transmitter for supplying a radio signal to waysidestations.

Control circuit 43 also provides capability to increase or decreaseelectromagnetic flux in the wheel axles in order to prevent slippage, asdescribed below.

FIG. 5 illustrates usage of the concept of “magnetraction”. Thisprinciple is used to stop train wheel slippage during power pulling,downhill braking, and stationary braking. As described in conjunctionwith FIGS. 1 and 4, the i magnetraction force is controlled by controlcircuit 43, either by computer or manually when needed. Particularly,wiring coils 22 a, 22 b (FIG. 1) are energized when slippage isdetected. Thus, electromagnetic forces are generated to stop theslippage and hold wheels 23 a, 23 b, 23 c, and 23 d tighter to thetrack. In this use of magnetraction wheels 23 a, 23 b, 23 c, and 23 dare the driving wheels of the locomotive.

In the use of magnetraction, the reason for the increase in traction dueto the increase in magnetic flux is that the flux pattern 53, shown inFIG. 5, essentially increases the wheels traction force, due to theattractive flux field. This electromagnetic power provided to the wheelsmay be modulated or applied fully, depending on conditions, and may beoperator or computer controlled. Basically, instead of dispensing sandon the track, as is conventionally done, electromagnetic energy is usedto stop slippage and increase traction. By employing electromagneticforce to increase traction, damage to wheels and rails if slippage wereto occur is avoided.

As shown in FIG. 6, an electromagnetic wheel loading means 60 may beemployed instead of, or in addition to, including the wheels in amagnetic circuit. The wheel loading means preferably comprises anelectromagnet 61 that is non-interfering with other train trackfunctions and devices. The electromagnet pulls the train downward towardthe track, making the train artificially heavier, during which time thetraction increases due to the increase in friction caused by the normalforce exerted by the electromagnet. The force of electromagnet 61 iscontrollable by control circuit 43, shown in FIG. 4. The increasedtraction enables locomotives to pull greater loads up steep grades.While employing electromagnetic wheel loading means 60, appropriateguards (not shown) for foreign debris, such as loose rail spikes, shouldbe utilized.

Thus the invention enables prompt location of damage due to crackedrails and also reduces slippage. Further, the cracked rail detection isprovided at high efficiency and low cost. Additional tractive effort canalso be gained by use of this invention, allowing increased loads to behauled on upgrades compared with locomotives not employing theinvention.

While only certain preferred features of the invention have beenillustrated and described, many modifications and changes will occur tothose skilled in the art. It is, therefore, to be understood that theappended claims are intended to cover all such modifications and changesas fall within the true spirit of the invention.

What is claimed is:
 1. An electromagnetic system for railroad trackcrack detection and traction enhancement adapted to be carried aboard arail vehicle, said system comprising: first and second wheel axles; afirst pair of wheels supported on said first axle; a second pair ofwheels supported on said second axle; a first one of the wheels of saidfirst and second pairs being adapted to contact a first rail of saidrailroad track; a second one of the wheels of said first and secondpairs being adapted to contact a second rail of said railroad track; afirst wiring coil wound on the first one of said axles; a second wiringcoil wound on the second one of said axles; a power source coupled toeach of said wiring coils for supplying power to produce electromagneticflux in a magnetic circuit comprising (a.) said first pair of wheels andsaid first axle, (b.) said first rail, (c.) said second pair of wheelsand said second axle, and (d.) said second rail; and a magnetic fluxsensor for monitoring a flux pattern produced by said magnetic circuitand for generating an output indication if the flux pattern varies. 2.The electromagnetic system of claim 1 wherein said wiring coils arephased to induce opposite magnetic north-south pole pairs in each ofsaid wheel axles and to induce opposite magnetic north-south pole pairsin each of said first one of the wheels of said first and second parirs.3. The electromagnetic system of claim 2 further comprising means forgeographically locating a position where said flux pattern is detectedto vary.
 4. The electromagnetic system of claim 3 wherein said means forgeographically locating a position is a Global Positioning System (GPS).5. The electromagnetic system of claim 1 further comprisingelectromagnetic wheel loading means coupled to said power source, forgenerating an artificial load imposed by said vehicle on said railroadtrack.
 6. The electromagnetic system of claim 5 wherein said powersource comprises a generator driven by rotation of a wheel on saidrailroad track.
 7. The electromagnetic system of claim 5 wherein saidwheel loading means comprises an electromagnet.
 8. The electromagneticsystem of claim 5 wherein said power source comprises a generator drivenby a locomotive prime mover.
 9. The electromagnetic system of claim 1further comprising means for geographically locating a position wheresaid flux pattern is detected to vary.
 10. The electromagnetic system ofclaim 9 wherein said means for geographically locating a position is aGlobal Positioning System (GPS).
 11. The electromagnetic system of claim1 wherein said power source comprises a generator driven by rotation ofa wheel on said railroad track.
 12. The electromagnetic system of claim1 wherein said power source comprises a generator driven by a locomotiveprime mover.
 13. An electromagnetic system for railroad track crackdetection and traction enhancement adapted to be carried aboard arailroad locomotive, said system comprising: first and second wheelaxles; a first pair of wheels supported on said first axle; a secondpair of wheels supported on said second axle; a power source included onsaid locomotive; electromagnetic wheel loading means coupled to saidpower source, for generating an artificial load imposed by saidlocomotive road track; and a control circuit for providing power fromsaid power source to said wheel loading means when wheel slippage isdetected during power pulling and downhill braking, and duringstationary braking.
 14. The electromagnetic system of claim 13 whereinsaid wheel loading means comprises an electromagnet.
 15. A method ofdetecting a broken rail of a railroad track comprising the steps of:forming a complete electromagnetic circuit joining one rail of the trackat two locations on the one rail with a second rail of the track at twolocations on the second rail, respectively; moving the electromagneticcircuit along the track so as to encompass the two locations on each ofsaid first and second rails within an area moving along the track; anddetecting a change in magnetic flux in said circuit as an indicationthat said area encompasses at least one crack in at least one of therails.
 16. The method of claim 15 including means for geographicallylocating a position along the track where said at least one crack hasbeen found.
 17. The method of detecting a broken rail of claim 15wherein said electromagnetic circuit encompasses a respective wheelcontacting the track at each of the two locations on the one rail,respectively, and at each of the two locations on the second rail,respectively.
 18. A method for detecting, from a moving rail vehicle, abreak in either rail of a pair of rails on which said vehicle is moving,said vehicle including at least a first pair of wheels supported on afirst axle and a seoncd pair of wheels supported on a second axle, saidmethod comprising the steps of: forming a complete magnetic circuitcomprising said first and second pair of wheels, said first and secondaxles, and a portion of each of said rails situated between the wheelsof said first pair and the wheels of said second pair, respectively;generating constant magnetic flux within said magnetic circuit; andmonitoring the magnetic flux within said magnetic circuit to detectvariation in the level of said flux as an indication of a broken railsituated between the wheels of said first pair and the wheels of saidsecond pair, respectively.
 19. The method of claim 18 including the stepof ascertaining a geographic location for each detected break in a rail.20. A method of increasing friction between a railcar and a railroadtrack, said railcar including a source of electrical power, comprisingthe steps of: detecting wheel slippage during power pulling and downhillbraking; and employing said electrical power to generate anelectromagnetic field between said railcar and said railroad track whilesaid wheel slippage is detected and during stationary braking, such thatsaid electromagnetic field acts to pull said railcar downward towardsaid track.